// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
// Copyright (C) 2009 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_EIGENBASE_H
#define EIGEN_EIGENBASE_H

namespace Eigen {

/** \class EigenBase
 * \ingroup Core_Module
 *
 * Common base class for all classes T such that MatrixBase has an operator=(T) and a constructor MatrixBase(T).
 *
 * In other words, an EigenBase object is an object that can be copied into a MatrixBase.
 *
 * Besides MatrixBase-derived classes, this also includes special matrix classes such as diagonal matrices, etc.
 *
 * Notice that this class is trivial, it is only used to disambiguate overloaded functions.
 *
 * \sa \blank \ref TopicClassHierarchy
 */
template<typename Derived>
struct EigenBase
{
	//   typedef typename internal::plain_matrix_type<Derived>::type PlainObject;

	/** \brief The interface type of indices
	 * \details To change this, \c \#define the preprocessor symbol \c EIGEN_DEFAULT_DENSE_INDEX_TYPE.
	 * \sa StorageIndex, \ref TopicPreprocessorDirectives.
	 * DEPRECATED: Since Eigen 3.3, its usage is deprecated. Use Eigen::Index instead.
	 * Deprecation is not marked with a doxygen comment because there are too many existing usages to add the
	 * deprecation attribute.
	 */
	typedef Eigen::Index Index;

	// FIXME is it needed?
	typedef typename internal::traits<Derived>::StorageKind StorageKind;

	/** \returns a reference to the derived object */
	EIGEN_DEVICE_FUNC
	Derived& derived() { return *static_cast<Derived*>(this); }
	/** \returns a const reference to the derived object */
	EIGEN_DEVICE_FUNC
	const Derived& derived() const { return *static_cast<const Derived*>(this); }

	EIGEN_DEVICE_FUNC
	inline Derived& const_cast_derived() const { return *static_cast<Derived*>(const_cast<EigenBase*>(this)); }
	EIGEN_DEVICE_FUNC
	inline const Derived& const_derived() const { return *static_cast<const Derived*>(this); }

	/** \returns the number of rows. \sa cols(), RowsAtCompileTime */
	EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index rows() const EIGEN_NOEXCEPT { return derived().rows(); }
	/** \returns the number of columns. \sa rows(), ColsAtCompileTime*/
	EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index cols() const EIGEN_NOEXCEPT { return derived().cols(); }
	/** \returns the number of coefficients, which is rows()*cols().
	 * \sa rows(), cols(), SizeAtCompileTime. */
	EIGEN_DEVICE_FUNC EIGEN_CONSTEXPR inline Index size() const EIGEN_NOEXCEPT { return rows() * cols(); }

	/** \internal Don't use it, but do the equivalent: \code dst = *this; \endcode */
	template<typename Dest>
	EIGEN_DEVICE_FUNC inline void evalTo(Dest& dst) const
	{
		derived().evalTo(dst);
	}

	/** \internal Don't use it, but do the equivalent: \code dst += *this; \endcode */
	template<typename Dest>
	EIGEN_DEVICE_FUNC inline void addTo(Dest& dst) const
	{
		// This is the default implementation,
		// derived class can reimplement it in a more optimized way.
		typename Dest::PlainObject res(rows(), cols());
		evalTo(res);
		dst += res;
	}

	/** \internal Don't use it, but do the equivalent: \code dst -= *this; \endcode */
	template<typename Dest>
	EIGEN_DEVICE_FUNC inline void subTo(Dest& dst) const
	{
		// This is the default implementation,
		// derived class can reimplement it in a more optimized way.
		typename Dest::PlainObject res(rows(), cols());
		evalTo(res);
		dst -= res;
	}

	/** \internal Don't use it, but do the equivalent: \code dst.applyOnTheRight(*this); \endcode */
	template<typename Dest>
	EIGEN_DEVICE_FUNC inline void applyThisOnTheRight(Dest& dst) const
	{
		// This is the default implementation,
		// derived class can reimplement it in a more optimized way.
		dst = dst * this->derived();
	}

	/** \internal Don't use it, but do the equivalent: \code dst.applyOnTheLeft(*this); \endcode */
	template<typename Dest>
	EIGEN_DEVICE_FUNC inline void applyThisOnTheLeft(Dest& dst) const
	{
		// This is the default implementation,
		// derived class can reimplement it in a more optimized way.
		dst = this->derived() * dst;
	}
};

/***************************************************************************
 * Implementation of matrix base methods
 ***************************************************************************/

/** \brief Copies the generic expression \a other into *this.
 *
 * \details The expression must provide a (templated) evalTo(Derived& dst) const
 * function which does the actual job. In practice, this allows any user to write
 * its own special matrix without having to modify MatrixBase
 *
 * \returns a reference to *this.
 */
template<typename Derived>
template<typename OtherDerived>
EIGEN_DEVICE_FUNC Derived&
DenseBase<Derived>::operator=(const EigenBase<OtherDerived>& other)
{
	call_assignment(derived(), other.derived());
	return derived();
}

template<typename Derived>
template<typename OtherDerived>
EIGEN_DEVICE_FUNC Derived&
DenseBase<Derived>::operator+=(const EigenBase<OtherDerived>& other)
{
	call_assignment(derived(), other.derived(), internal::add_assign_op<Scalar, typename OtherDerived::Scalar>());
	return derived();
}

template<typename Derived>
template<typename OtherDerived>
EIGEN_DEVICE_FUNC Derived&
DenseBase<Derived>::operator-=(const EigenBase<OtherDerived>& other)
{
	call_assignment(derived(), other.derived(), internal::sub_assign_op<Scalar, typename OtherDerived::Scalar>());
	return derived();
}

} // end namespace Eigen

#endif // EIGEN_EIGENBASE_H
